Snap action device



OCt. 28, G. M HAUSLER 2,429,812

sm AcTloN DEVICE Filed March 12,*-1943 mlm r Inventor: George M. Hausler,

is Attorney bility.

`to GeneraLElectric 'v New Yorls VGeorge M. Hausler, Ballston Lake, 3N. Y., assi`znon Company, a corporation of 1 .Ap'piianon March 12, 1943. serial rzoffrraaza comms. ,(ci. 26o-iev) My invention relates to snap; action -devices,. more particularly tosnap acting switches and the l like, and'has f or its object the provision of a newand novel device of this character which scomposed of a minimum number of parts `andwhich.

is slmpleand inexpensive in construction with-v out sacrificey of capacity, reliability-and dura- In carrying out my invention in oneform I utilizea switch member comprising a single unitary strip oi spring material'slotted toprovide a pair of outer tension membersand a central pair of spaced apart compression members in opposing. relation, such as described and claimed inv my copending application Seria1 No'.435.220, filed March 13,' 1942, now Patent No.y 2,332,911 The juxtaposedends of the compressionmembers each pivotally engages a supportingand actuating member which is preferably mounted for reciprocalmovement in a direction normal to the plane'ofthe sprlngvstrip thereby to move the pivoted ends of thecompression members ovei'-, 'f

centerwith. respect to the;A center lineof the tension members. .The actuating member andthe outer ends of the spring stripare each provided with suitable stops to limit .the movement various parts of the device.

It vis;y a particular object of my invention toy provide a snap actionswitch of the above characterfwhich after actuation from a, normal posi-. tion shall remain in its'actuated. .position untilV manually resetbymeans other than the actuating means. For this purpose I bias the actuating .i

member to a normal positionwhlch is so disposed in relation to the location of the stop members that the spring strip will remainfin either 'of two alternative .equilibrium positions on opposite sides of the pivot points of thecompression members with. .theactuating member inits normal p0si.

tion. y .Thus if the spring strip is. in that position ofequilibrium in which movement of the actuating member brings'the'plvoted ends of the com-` pression members toward thevplane of the strip, snap action is effected by thus moving the actuating member to move the pivoted ends of the compression members overcenterywith respect to the plane of the strip. When the spring strip is in its other4 posii'ton of equilibrium movement of the actuating member can have n'o effect, since it l i been once vactuated the actuating movement was approximately one rent oi the motor thousands of times. l..

Foralmore complete understanding .of my invention and for av further appreciation of itsobf jects and advantages reference should'now'be had to the following detailed specication taken in' conjunction with the accompanying drawings in. which Fig. 1 is a plan view, partly in section, of a snap action relectric switch emboding my invention; Fig. 2 is aside elevation., partly in section, ofthe device shown in Fig. 1 with'the cover Referring now to the drawings, I have shown l my invention in oneform as applied to a push button operated snapaction electric switch.l T he switch is mountedin a casing Ill whichis preferably made of insulating` material molded to a suitable configuration and provided with aninsulating covervllla. The switch vmember itself is a unitary flat strip of spring material Igl slotted at. I2 and I3 to provide a pair of outer tension arms. and l5 and a centralpair of opposing compression arms I6 and I1 in spaced relation.

Thecornpression arms l5 and l1 are slightly de` f ormablein compression and are formed by dividing' a single central arm transversely inthe region of its center so that the inner ends' of the arms l5 vand I1 are in juxtaposed relation. At opposite by. 'movementpfp the actuating member. further movement 2 of the. actuatingmemberlwill have :no effect npon;the-. 'device until it isilrst'reset bythe .resetbuttonl f `A snapaction vdevice of the above type may be f built in very-small sizesandywhen used tofactuate the gcontactsof an' electric switch, theg-switoh .1 possesses remarkably vhigh interrupting capacity.. for both. alternating and direct currentin comparison toitsphysical dimensions. The switch is alsov suitable vfor-precision work, sincegmoveement of the actuating member requiredto. effect i clrcuitmaking or .circuit breaking'. movement oi` thecontacts is quite smalland remains substan; tially constant. y For example, in atypical switching devicein which the switch member of -s pring material. was approximately one inchin length outer ends of the strip II are mounted movable Contact members I8 and I9.

Slidably` supported in the casing I for rectilinear ymovement along a line substantially normal to the plane of the switch member II I provide an actuating and supporting member in the form of ls. push button comprising a shank portion or rod 30, la molded head portion 3I Aand a pair of bowedy spring strips 32. The spring strips.

32 are provided with slightly curved base sections 33 arranged for insertion in suitable slots in the head portion 3| of the push button along with one end of the rod 30.

portion 3l and the springs 32 themselves to the shank portion 30 of the slidable actuating member. The spring strips 32 are notched at their lower ends, as at 34, pivotally to support the jux.-

taposed inner ends of the deformable compression members I6 and I l. The springs 32 are .also biased outwardly to apply endwise forces to thev members I6 and Il, thereby to bend and spreadthe compression members and-force them The portions 33 of the i springs 32 serve frictionally lto `attach, the head out ofthe plane of the spring strip II on one abutting'endsV of the compression membersA I6` and Il. l

The slidable rod is provided at 35 with a suitable shoulder forming a seat for a compression spring 36 disposed between the shoulder 35 and aportion ofthe casing yIll toibias the entire pushbutton assembly outwardly, or as shown in the drawing in the upward direction. To limit Voutward movement of the actuating member the pushbutton head portion 3| is provided with aperipheral flange 3lV arranged to engage a portion oi the casing I0. Thus under the inuence of the spring the pushbutton actuating member normally assumes its uppermost position as shown at Figs. 2 and 3. Downward movement of the pushbutton is limited by the limit of compression of the spring36 between the shoulder 35 f and the lower portionof the casing I0.

rIfo provide alternativepositions of equilibrium for the spring stripv II on opposite sides of the pivoted ends ofthe compression arms I6 and I1 the casing I0 is provided with a pair of fixed c ontacts 40 on one side of the spring strip II and adjacent the movable' contacts I8 and I9 and a pair of stop members 4I and 42 on theother side of the spring strip I I and in spaced relation with respect to the fixedcontacts 40. The stop member 4I is movable and is mounted upon the end of avreciprocablereset rod 43 extending outside of the casing I0. The reset rod 43 is biased to a retracted position by means ofv a small compression spring 44 disposed between the casing I 0 and a shoulder- 45 upon the reset rod. As indicated at Figs. 2 and 3 the xed contacts 40 and the stop members 4I and 42 are so disposed that they determine two alternative positions of equilibrium of the spring strip II on opposite sides of the` pivoted ends ofthe compression arms I6 and I1 when the actuating member 30, 3I, 32 is in its vagainst the upper stops 4I and 42 the'plane of the spring strip will be above the pivot points of the compression members'IS and I1 so that the strip will remain lin this tripped position until moved or reset by some external force.

With the `foregoing understanding of the various elements of my invention and their interrelation in an'actual operative device, the mode of operation of the `'device itself will be clear from thefollowing brief description. Referring iirst to Fig. 2 the switch is shown in its normal contact engaging position with the actuating member 30 in its normal -biased position, the plane of the spring strip belowthe pivot points ofthe compression members Il -and I1 thereby to engage `the contacts, and the reset rod 43 retracted. vIf now the pushbutton actuating member 30, 3|, I2 is depressed by any suitable means, for example, f manually, thermostatically, or by fluid pressure, the pivoted inner ends. of the compression arms IB and I1 will be moved toward the .plane of thespring strip I I and finally overcenter with respect to this plane. As soon as such overcenter movel ment occurs the outer'ends of the spring strip4 will move upwardly with a. snap action under the iniluence of the compression members I6 and I1 and the bowed spring 32 tending to-spread the compression members and force them apart. It the actuating member 30 is now released it will be forced back vto its normal position by the compressiony springf 38 and the device will be in the position shown at Fig. 3. v

It will be noted from Fig. 3 that in moving back to its normal position the actuating member30 does not again move the pivoted ends of the compression members I6 and I1 overcenter with respect to the plane of the tension members" or.'

l I5 in the upperor tripped position. Thus release of the actuating member will` not effect automatic return of the movable contacts to their lower po` sition. The device may now be reset to contact engaging position `by depressing the reset rod 43.

By this movement one end'of the spring strip II 'the iixed stop member 42 until the tension members I4 and I5 move overcenter with respect to the pivoted ends of the compression members I6 and I1. As soon as this overcenter movement takes place both outer ends of the spring strip and the movable contacts I8 and I9 are moved into engagement with the fixed contacts 40 with a snap action independently of further movement of the reset rod 43 and under the influence of the compression members I6 and l1 and thespreading spring 32. Upon release of the reset rod 43. it will be automatically retracted by the compression spring 44 and' the entire device will again bein the position shown at Fig. 2.

While I have shown a particular embodiment of my invention by way of illustration many further modifications will' occur to those skilled in the art and I, therefore, wish to have it understood that I intend in the appended claims to equilibrium, and .means 'for moving` said tension Amember overcenterwith respecdtovthe pivoted yeildsof said'compressio'nmembersfwhen Said'ten .g5

whensaid ltension member is in the vcover au such modificarn-s .asffufwumn `the :true `spirit and' scope foff :my invention :'Letters'Patent ortho/United 'States`-jis'z `l. -Aijs'nap action 'device comprisingja base, an :5.v actuating member movablyy mounted' uponxsaid base," a 'pair of compression jmembersL ,pivotally' mounted; 1 upon rsaid actuating memberand ex'- tending in opposite directions. therefrom, a tenf ssicmimember connected. betwee'rr't'heA free ends li) Y `of-fsa'i'd compressionmembers, stopumeans positioned'in" spaced relation adjacent the free ends of fsa'id ficompression-membersto determine two. i

sion lembenWithf-'respect 'to Ia "predetermined 1.5 :normal position of said actuating member, means -for biasing said .actuating membervto 'said normal position, said actuating member being movable `againstits bias vto move'the pivoted yends of said compressionmembers overcenter with respectto 20 tile 'center lin'e 'of 'said'tension member when'said tension member is in one .of saidgpositions-of sion member is in the other of saidpositions of equilibrium.v

2. A snap action device comprising .a base, an

-actuating member movably mounted upon said base, `apair of compression members pivo'tally Iil() mounted upon lsaid actuating member and extending in opposite directions therefrom, a tension member connected between theffreeends of said compression members, twopairs rof stop 'members for `limiting movement of ythe ireefends 35 of lvsaid compression members in each direction 'longitudinally of the vdirection of movement of said. actuating member, the stop members of said pairs beingin spaced relation adjacent each free 'end `oi said compression members thereby to der40 is i'nonefof said equilibrium positions; and means for 'movingat least one of said stop members to move said tension member overcenter with respect tothe. pivoted ends of said compression members other of said 55 positions of equilibrium.

3-. A snap action device comprising an integral istrip o'f'lspring' material slotted longitudinallyto form a plurality rof `substantially parallel resilient farms connected together at opposite louter ends B0 of said strip, one 'of said Iarms being divided transversely intermediate its vends to .provide a .pair vbf spaced apart opposing compression members having their ends in juxtaposition, an ac;- tuating'and supportingmember disposed between 55 lthe .juxtaposed ends of said compression mem'- bers, said actuating member-being wider between said juxtaposed ends'of said compression members than lthe space between said ends in the pla-ne of said strip, means for supporting saidf'70 actuating fmember for movement substantially normal tothe plane of said strip, `pivotal means for"con'nectirngy the juxtaposed ends of said compression Imembers to said actuating member thereby 'to support said spring strip, means for 75 f means. ka Jfixed contact :posit spaced relationadja'cen-t thefree en' n compression members'to determine twoalter biasingy said yactuating member to a. predeter mined nor'rnalfposition, twopairs o'f'stop mem-f-f bers arranged in spaced relationtoi'deterjrnine-v twdA alternative positions -v of equilibrium xzof -sai'cfi stripon opposite sides of the `p'ivotfpoints ofA said compression .members fsaid actuating member being movable againstits bias tomovefthe'pivoted .ends lofsaid compression members ,overcenter With respe'ctto the plane of said vstrip when said. A stripis'in one'of. said positions ofequilibrium,l y 'andk means .for moving .said spring strip over-f centerfwi'th respect tothe pivoted endsfo said compression iin'embers .when said spring-strip' inthe other' oj'fs'aid positions of equilibrium.

.14. snap action f 'electric'` 'switch comprisinpa base, arecipr'ocable actuating and Supportingard slidably mounted upon Asaid .base,ya "pairo'flcornf-v pression members pivotall`yv-mounted Hsaid-v actuating rod and extending inopposite' direction* therefrom, a tension member connectedbetween the "free ends of vsaid compression :membera af movable contact `mounted :uponthe 4'free en lot at least onepf said compression 'm'enb top tive positions of"eql'i'ilibrium of said tensionm-e'mber with respect 'toma vpredetermined normal .po-

sition of said actuatingrod, vmeans .for `biasing said actuating rod 'to said normal position, said 'actuating-rod being movable against its bias tov move the .pivoted ends of said compression members overcenter with respect to the center line of said tension vmember when saiditension member is in oneposition of equilibrium with said ycontacts engaged, vrand means -ior 'moving said tensionmember overcenter with respect to the pivoted 'ends of -said compression members .to

`reset said contacts when said tension member is in 'the `other of ysaid positions of Iequilibrium with said contacts disengaged.

5. A snap action electric .switch comprising a base, an integral strip offspring material slotted longitudinally to .form a plurality of substantially parallelresilientarms connected together at op- .posite louter ends of .said strip, yone of said rarms being divided transversely intermediate its ends to provide ra pair of `spacedapart opposing'compression members havingtheir `ends in juxtapo- 50 sition, a movable conta'ctmounted on,at least one outer end .of said strip, an actu-ating and supportingrod disposed between the ljuxtaposed ends `of said compression members,'s`aid actuating rod being wider between said juxtaposed ends :of said 'compression members than the space be- Atween said ends in theplane of said strip, pivotal means for slidably supporting-said actuating rod yfor movement substantially normal to the Aplane y 'of said strip, .pivotal means .for 'connecting'the juxtaposed "ends of said compressiony members to said "actuating rod 4thereby to support `said strip, upon Asaid rod, two pairs of. stop members arranged 'to :determine two alternative positions of equilibrium of said strip on opposite sides 'ofthe pivot .points 'of said compression members, one

of said pairs of stop members including .aiixed contactmounted upon said base for cooperation with said movable Ycontact and the yother o'f said pairs of stop members including a movable vreset member, said 'actuating member being .movable against its bias rto move the pivoted endsof lsaid compression'members overcenter with respect to the plane of said strfipwhe'n said strip is in .its

contact engaging position lof'fequilibrium and said reset member being movable to move v'the .plane ofsaid spring strip overcenter with respect to thepivoted ends of` said compression `members when saidf spring strip is in itsjcontact disengagin'gr yposition ofA equilibriumand said actuating rod is in said normal position.

A6; A snap action device comprising an integraal strip of spring material formed to provide a pair of parallel outer tension arms and a pair of opposing inner compression'arms, a movable actuating member slidably mounted for reciprocal movement substantiallynormal to the plane of said 'spring strip, means for' pivotally mounting the juxtaposedendsV of saidrcompressiori` arms upon said actuating member forovercenter movement with respect to thev plane of saidJstrip, said actuating" member being wider between said juxtaposed ends than the space between said ends in the plane Ofsaidstrip, two vpairsvof 'stop' members forli'miting movement of thejouter ends of 'saidhst'rip inibotb directions normal tothe piane of `said strip, jmeans for biasing said ac'- tuating member to a predetermined normalposition such thatsaid'pairs of stopmembers `determine alternative positions of` equilibrium of saidst'rip on opposite sides of the pivot points of said compression members, said actuating member being movable against its bias to move the pivoted ends o1. `said compression members overcenter with respect to the plane of said spring strip in one of said equilibrium positions, and

means associated with said stop' means for moving the plane of said spring strip overcenter with respect Vto said pivot points when said strip is in its other equilibrium position and said actuating member is in its normal position.

GEORGE M. H AUSLER..

REFERENCES CITED ,The following references are of recordin the v le of this patent: ,UNITED STATES PATENTS 

